9727762 Bennett This study examines how the pulmonary and cardiovascular systems respond to increased metabolic demands for increased oxygen delivery and carbon dioxide removal in very different tissues: the skeletal musculature and the intestine. Is the pattern of increased ventilation and circulation stereotyped, such that the same response (heart rate, stroke volume, breathing frequency, and tidal volume) is used for equal energetic demands in the two different tissues, or is it plastic, dependent on which tissue is active? If both tissues are active simultaneously, which receives priority allocation for oxygen delivery and carbon dioxide removal? Large reptiles will be used as model systems to investigate these patterns, because metabolic increments associated with digestion are extraordinarily large in these animals, approaching those associated with physical activity.
